Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs

Samium Gromoff
2004-02-03T06:56:25Z

> > The machine is a dual P3 450MHz, 512MB, aic7xxx, 2 disk RAID-0 and
> > ReiserFS. It's a few years old and has always run Linux, most
> > recently 2.4.24. I decided to try 2.6.1 and the performance is
> > disappointing.
>
> 2.6 has a few performance problems under heavy pageout at present. Nick
> Piggin has some patches which largely fix it up.

I`m sorry, but this is misguiding. 2.6 does not have a few performance
problems under heavy pageout.

It`s more like _systematical_ _performance_ _degradation_ increasing with
the pageout rate. The more the box pages out the more 2.6 lags behind 2.4.

What i`m trying to say is that even light paging is affected. And light
paging is warranted when you run, say, KDE on 128M ram.

Go measure the X desktop startup time on a 48M/64M boxen--even light paging
causes 2.6 to be just sloower. Also the vm thrashing point is much much earlier.

Ask Roger Luethi for details.

regards, Samium Gromoff